IndexedDB has great support in modern browsers but can be a bit intimidating to start working with. This video uses the newest version 5 of Jake Archibald's idb-keyval library to simplify what you need to know to get started.
If you have worked with localStorage or sessionStorage and like using Promises with their then( ) and catch( ) methods, then you can use IndexedDB.
Code from Video: https://gist.github.com/prof3ssorSt3v3/b922b5cf9f34e85578c9bff75ccd4000
Link to idb-keyval Github Repo: https://github.com/jakearchibald/idb-keyval
Practical LocalStorage video: https://www.youtube.com/watch?v=Lu-eBtYTRBY
Upcoming Deeper Dive into vanilla JS for IndexedDB video: COMING SOON